Method of controlling the stoking of furnaces.



E. A. EMERY. METHOD OF CONTROLLING THE STOKING 0F FURNACES.

APPLICATION FILED FEB. 20. 191 t nted uly 24, 1917.

4 SHEETSSHEET l- E. A. EMERY.

METHOD OF CONTROLLING THE STOKING 0F FURNACES.

APPLICATION FILED FEB. 20,. I915- 4 SHEETS-SHEET 2- Wye/mu" Evin M H. 5/11 E. A. EMERY.

METHOD OF CONTROLLING THE STOK'ING F FURNACES.

APPLICATION FILED FEB. 20. 1915.

1 %3%3 l 7, Patented July 24, 1917.

4 SHEETSSHEET 3.

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E. A. EMERY.

v METHOD OF CONTROLLING THE STOKING 0F FURNACES.

APPLICATION FILED FEB. 20. 1915.

@% 3 1 Y n Patented July 24:, 1917.

4 SHEER-SHEET 4.

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EDWIN A. EMERY, OF ST. LOUIS, MISSOURI.

METHOD OF CONTROLLING THE STOKING OF FURNACES.

Specification of Letters Patent.

Patented July 2%,- 191?.

Application filed February 20, 1915. Serial No. 9,559.

To all whom it may concern:

Be it known that I, EDWIN A. EMERY, a citizen of the United States, residing at city of St. Louis, State of Missouri, have invented a certain new and useful Improvement in Methods of Controlling the Stoking of Furnaces, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is a vertical sectional view through the center of an under-feed furnace and showing the same equipped with an automatically operating hydraulically actuated stoking mechanism particularly designed for practising my improved method.

Fig. 2 is an enlarged detail sectional view taken approximately on the line 22 of Fig. 1.

Fig. 3 is a plan view of one of the segments or sections of the grate.

Fig. l is a detail elevational view showing the connection between the grate sections and a grate operating ring.

Fig. 5 is a detail elevational view of the connections between the grate ring and its actuating shaft.

Fig. 6 is a vertical section taken through the center of a lever operating thermostat utilized in the apparatus.

Fig. 7 is a vertical section of a pilot valve and showing a portion of the lever which actuates the same.

Fig. 8 is a vertical sectional view of a control mechanism made use of in the apparatus.

Fig. 9 is a horizontal section. taken approximately on the line 9-9 of Fig. 8.

Fig. 10 is a detail elevational view of a pilot switch which is adapted to take the place of the pilot valve when my improved apparatus is electrically operated and motor driven.

Fig. 11 is an elevational view of the control mechanism for the electrically operated apparatus.

Fig. 12 is a vertical section taken approximately on the line 12-12 of Fig. 11 and diagrammatically showing the electrical connections between the control device and the motor.

Fig. 13 is a detail sectional view showing the fuel feeding plunger, and the electrically operated mechanism associated therewith.

Fig. 14 is a vertical sectional view of a furnace of my improved construction and showing manually operable stoking mechanism associated therewith.

Fig. 15 is a diagrammatic view of a modified form of thermostat which is adapted to be used in the apparatus.

Fig. 16 is a diagrammatic view illustrating means utilized for efl'ecting an automatic operation of the stoking mechanism at a predetermined time.

My invention relates broadly to an improved method of automatically controlling the stoking of furnaces and the like, and while particularly intended for use in connection with household heating furnaces, can be advantageously employed in connection with furnaces whose heating effect may be utilized for any one of a wide variety of purposes.

The principal object of my invention is to provide an improved method whereby the stoking or firing of a furnace may be accomplished entirely automatically and which furnace will maintain a temperature within a predetermined range of variation.

My improved method contemplates the periodical introduction of fuel into a furnace, the volume of fuel introduced at each operation being largely in excess of the immediate needs, then automatically terminating the operation of the stoking mechanism regardless of the degree of temperature, effecting a discharge of ashes from the lower portion ofthe bed of burning fuel simultaneously with the introduction of fresh fuel to the upper portion of said bed, then c0ntrolling the combustion of the fuel thus introduced by means of a temperature controlled device, such as a thermostat, such method being entirely automatic and dependent upon the rise and fall of the temperature through a predetermined range of variation.

Further objects of my invention are, to provide an improved process whereby the stoking or firing operations are automatically controlled; to provide a method wherein a fluid-pressure operated means, or an electrically operated means, may be interchangeably used for effecting the stoking or firing operations; to provide for the automatic operation of the grate sections for effecting a discharge of ashes and refuse resulting from combustion; to pfovide for the automatic control of the draft openings to insure the proper rate of combustion; to

rovide for the regulation of the amount of fuel introduced at each operation of the stoking mechanism and the regulation of the amount of fuel introduced at any one cycle of operation; to utilize the effect of heat upon fluidsor metals to control the movements of parts of the operating mechanism; to provide means for maintaining a constant depth of fuel in the combustion chamber; to provide for the dumping of the grates to effect the discharge of forei 'n matter, such as slate or other refuse wit out disturbing the operation of the furnace; to provide simple means for the regulation of the range of temperature through which the furnace operates, and further, to provide an improved method of controlling combustion and the renewal of fuel in the fire box of boilers or furnaces whereby it is possible to maintain a practically continuous temperature within fixed limits of variation for unlimited periods dependent solely upon the storage capacity of the plant or apparatus utilized for practising the method.

In addition to the foregoing, other objects and advantages of my invention will be hereinafter pointed out, or become obvious and the manner of practising the method will be understood by reference to the accompanying drawings which show a practical form of apparatus for carrying out my improved method. In these drawings the numeral 10 designates the body of an ordinary under-feed furnace, the same being positioned on top of a housing 11 which serves as an ash-pit, and located in the door opening into said ash-pit is the usual draft damper 12.

Leading fromthe upper portion of the furnace is the usual smoke pipe 13, the same being provided with a check draft damper 14. Positioned to the side of the body of the furnace is a fuel hopper 15, the lower end of which communicates with a horizontally disposed feed pipe 16 preferably square in cross section and the inner end of said pipe is curved upwardly and terminates in the center of the lower portionof the furnace. The inner end of this feed pipe is preferably circular in cross section.

The grate as contemplated by my invention is frusto-conical in form and is made up of a series of substantially triangular sega ments 17, the same being provided at their ends with trunnions 18 which rest in suitable bearings formed in the upper portion of housing 11 and in the inner end of feed pipe 16.

Formed integral with each grate section is a depending lug 19, the same being perforated and connected by a suitable link 20 to a ring 21, which latter is preferably of inverted U-shape in cross section, and being mounted to rotate freely upon rollers 22. These rollers are journaled in suitable brackets which are carried by the feed pipe 16, and thus as ring 21 is moved backward and forward upon said rollers, all of the grate sections will be uniformly and simultaneously rocked, thereby agitating the lowermost strata of the bed of fuel and tending to shake down or discharge the ashes. By reason of the pitch of the grate sections, the fuel discharged from the upper inner end of the feed pipe will be evenly distributed over the surface of the entire grate.

Where my improved furnace is operated by a fluid medium, such as water under pressure, an ordinary reciprocating hydraulic motor 23 is located on a frame bolted to an extension of the ash-pit 11 adjacent to the held plate is adapted to yield rearwardly and permit the plunger to make its full forward stroke, in the event that a piece of slate or hard foreign substance lodges between the edge of said plate and the forward upper edge of the plunger.

Seated in the lower portion of the plunger 24 is a rod 27 carrying a slotted arm 28. The bearing which holds this rod 27 is slotted and passing through said hearing at right angles to the slot are bolts 27 which extend into corresponding grooves 27 formed in said rod, and thus said rod is adjustably held in its bearing. To shift the position of said rod and arm 28 it is only necessary to loosen bolts 27 a and swing the arm to the desired position and then tighten said bolts to lock the rod in its adjustedposition. (See Fig. 2.) Journaled in suitable'bearings on one side of the feed pipe 16 is a rock shaft 29 upon which is loosely mounted one end of arm 30, the inner end of which carries a roller 31, the same occupying the slot in arm 28. -This arm 28 Fixed on rock shaft 29 adjacent to arm 30 is the lower end of a hand lever 32, the

same being provided with a spring-held latch 32*, the point of which normally engages a notch 33 in arm 30 and thus as said arm is vibrated, shaft 29.will be rocked.

Fixed on shaft 29 is an arm 34 and connected to the outer end thereof is a link 35, the same being connected to ring 21. Thus, as plunger 24 is reciprocated, shaft 29 is rocked and through the connections 34 and 35, ring 21 ,is actuated, thereby imparting rocking movement to grate sections 17.

Located at a convenient point on the body of the furnace 10 is a closed receptacle 36 which contains a fluid, preferably liquid, which will expand into vapor when heated, and leading from this receptacle to the chamber in the lower portion of the housing 737 is a pipe 38.

Located within this housing is a diaphragm 39 and positioned thereupon is an upwardly projecting member 40 which is pivotally connected to a horizontally disposed lever 41. This lever is fulcrumed to a suitable bracket which extends upward from the housing 37 and connected to one end of said lever are the ends of chains or cables 42 and 43, the former leading to draft damper 12 and the latter leading over suitable pulleys to check damper 14 in smoke pipe 13.

Screw-seated in the upper portion of the bracket to which lever 41 is fulcrumed is a nut 44, the same serving as a bearing for the upper end of member 40, and interposed between said nut and a shoulder on said member is a compression spring 45. This spring, the tension of which is regulated by nut 44, normally tends to force member 40 and parts connected thereto downward.

Projecting from one side of the bracket to which lever 41 is fulcrumed is a sub stantially L-shaped bracket 46 to the upper end of the vertical leg of which is pivotally connected a bell crank 47 and carried by the end of the vertical arm of this bell crank is a roller 48 which normally engages against the high and low faces a and b of a plate 49, the same being adjustably fixed to lever 41.

Removably positioned on the horizontal arm of bracket 46 is a valve housing 50, the same being provided with chambers 50 and The partition between these valve chambers is provided with an opening 51 which is adapted to receive a downwardly opening valve 52, the same being carried by a stem 53 which extends upward through the top of the valve housing and carrying a compression spring'54, which latter bears against a pin or shoulder on said valvestem and tending tonormally raise the same.

The upper end of valve stem 53 bears against the underside of the horizontal arm of bell crank 47.

Leading from chamber 50 to the ash-pit with chambers 59 and 60.

of the furnace is a vent pipe 55, and leading from chamber 50 to a chamber within a control valve housing hereinafter described is a pipe 56.

Removably positioned on top of the feed pipe 16 adjacent to the hydraulic motor 23 is a housing 57, the same containing the valves and mechanism which control the operation of said motor.

Positioned within housing 57 is a double valve housing 58, the same being provided Arranged for sliding movement in the upper portion of chamber 59 is a cylindrical member 61 having the functions of a piston and carrying on its underside a disk valve 62, preferably rubber and which is adapted to engage a seat 63 which is formed around the mouth of passage way 64, the same leading into chamber 60.

A water supply pipe 59 is tapped into housing 58 and discharges directly into Interposed between the diaphragm and the horizontal plate forming a part of piston 61 is a compression spring 69 which tends to force said piston downward, and formed through the horizontal plate of said pisto zn is a comparatively small vent opening 0.

' Leading into chamber 59 above the piston 61 is an opening 71 to which leads pipe 56. Arranged to slide vertically within chamber 60 is a piston 72 provided with a horizontally disposed plate 73 and carried by the underside of this plate is a valve 74 preferably rubber and which is adapted to engage o-n aseat 75, which is formed at the upper end of a passage way 76. This passage way is formed through a tubular extension 77 of the housing 58 and said tubular extension projects through the wall of housing 57, and is connected to hydraulic motor 23 by a pipe 78.

Formed through plate 73 is a comparatively large vent opening 79. Formed through that portion of the cap plate 65 above chamber 60 is a vent passage way 80. Adapted to close the inner end of this passageway is a valve 81, preferably metal, the

.same being carried by the lower end of a and carried by the underside of valve 81 is an auxiliary valve 84 preferably rubber which is adapted to close the vent opening 79 in plate 73.

Interposed between cap plate 65 and horizontal plate 73 is a compression spring 85. J ournaled in suitable bearings in the housing 57 is a shaft 86 on which is loosely mounted a disk 87, the same being provided with a series of internally arranged ratchet teeth 88. Seated in this disk near its edge is a pin 89 which is adapted to engage against the stop pin 89, the same being removably positioned in any one of an annular row of apertures 90, the same being formed in the rear wall of housing 57.

Fixed to the hub of disk 87 is the inner end of a spiral spring 91, the outer end thereof being fixed to the housing 57. A short shaft 92 is journaled in the front wall of housing 57 and carried by the inner end of this shaft is a short arm 93 upon which is pivotally mounted a spring-held pawl 94, the point of which is adapted to engage ratchet teeth 88. Seated in the forward end of this pawl is an outwardly projecting pin 95.

Fixed tothe front wall of housing 57 is a pin 96 on which is loosely mounted a spring held pawl 97, the forward end of which is provided with[ a hook which is adapted to engage ratchet teeth 88 and projecting outwardly from the forward end of this pawl is a pin 98, the same occupying a position adjacent to pin 95.

Fulorumed on a pin 99 which projects inwardly from the front wall of housing 57 is a lever 100, one end of which bears on top of pin 68 and the opposite end overlying and bearing upon pins 95 and 98.

Fulcrumed on a pin 101 is a lever 102, one end of which bears on top of Valve stem 82 and the opposite end carrying a roller 103 which normally bears on the periphery of disk 87 and being adapted to engage in a notch 104 formed therein.

Fixed to the outer end of short shaft 92 is the upper end of an arm 105, the lower end thereof being slotted to receive a pin 106, the same projecting outwardly from the hydraulic motor piston rod 107 and which latter is connected directly to plunger 24.

When electric current is utilized for operating my improved stoking apparatus, housing 57 is removed and replaced by a housing 108 which contains certain electrically controlled mechanism hereinafter more fully described and an electric motor 109 takes the place of the hydraulic motor 23.

The shaft of the electric motor is provided with a worm 110 which meshes with a worm wheel 111, same being mounted on shaft 112 and connected to a crank on this shaft is a connecting rod 113, the same being also connected through the medium of a crosshead 24 to the rod of the plunger 24.

'A bracket 114 takes the place of valve housing 50 on bracket 46 and arranged on said bracket 114 is an electro-magnet 115. An armature 116 is pivotally mounted on bracket 114 in position to be attracted by said magnet and pivotally connected to the free end of this armature is a contact pin 117 which operates through a suitable bearing inthe bracket 114.

A flat spring 118 is fixed to bracket 46 and bears against the underside of horizontal arm of bell crank 47 and adjustably seated in and insulated from said bell crank is a contact pin or screw 119, with which pin 117 is adapted to contact.

Leading to pin 119 is one conductor 120 of a circuit, the other conductor 121 of said circuit leading to the motor 109. One end of the coil of magnet 115 is connected directly to bracket 114 by a conductor 122, the other end of said coil being connected by conductor 123 to an electro-magnet 124 which is located in the upper portion of housing 108. Connecting conductor 121 with magnet 124 is a conductor 125.

Mounted in the side walls of housing 108 is a stud 126 and loosely mounted thereon and insulated therefrom is a disk 127 provided with a series of internally arranged ratchet teeth 128. Fixed to the housing 108 is one end of a spiral spring 129, the inner end of which is fixed to the hub of disk 127. J ournaled in the housing 108 is a short shaft 130 to the outer end of which is fixed the upper end of an arm 131, the lower end thereof being bifurcated and engaging a pin 132, which latter is carried by the crosshead 24 of plunger 24.

Fixed on the inner end of shaft 130 is an arm 133, the same carrying a spring-held pawl 134 which engages the teeth 128 of ratchet wheel 127. Projecting outwardly from the forward end of pawl 134 is a pin 135.

Pivotally mounted on a pin projecting inwardly from housing 108 is a spring-held pawl 136 provided on its forward end with a hook which is adapted to engage the teeth 128, and projecting outwardly from the forward end of this pawl is a pin 137.

Pivotally mounted upon a pin 138 within the upper portion of housing 108 is a horizontally disposed arm 139, same being provided with an armature 140 which is located directly beneath the core of magnet 124 and shaft 126 is an arm 149, which is provided on its outer end with hook 150, the same being adapted to engage hook 148. Fixed to the hub of arm 149 is the inner end of a spiral spring 151, the outer end thereof being fixed to a pin 152 which is seated in and insulated from housing 108 and serving as a binding post for the attachment of one end of' a conductor 153 which leads to the 29 motor 109.

Formed in one of the walls of the housing 108 isa circular row of apertures 154,

and adapted to engage therein is a pin 155 of suitable insulating material, the same serving as a stop to limit the backward movement of arm 149 when same is released from dog 145. a

Seated in housing 108 is an insulated binding post 156, the inner end of which 30 carries a flat spring 157, the free end of which has rubbing contact with the peripheral surface of ring 144. A conductor 157 leads from conductor 123 to this last mentioned binding post.

Where it is arranged for stoking the furnace manually, the piston or connecting rod of the plunger 24 is directly connected to an arm 158, the same being fixed on a shaft 159 which is journaled in a suitable bracket 49 on the underside of hopper 15. Fixed to this shaft is a hand lever 160 which, when actuated, reciprocates the plunger 24 in the feed pipe 16. (See Fig. 14.)

VVhen the hydraulic motor is utilized for effecting the stoking of the furnace, the operation is as follows:

After the completion of the cycle of operations of the automatic stoking mechanism and before enough of the fuel has been consumed to establish temperatures within a predetermined range, the various parts of the control mechanism occupy the positions as illustrated in Figs. 6 to 9 inclusive.

The heat from the furnace acting on the liquid within container 36 causes same to vaporize and expand so that diaphragm 39 is acted upon to permit lever 41 to occupy a position where the high portion a of plate 49 bears against roller 48, thereby holding bell crank 47 in the position shown in Fig. 7 with valve stem 53 moved downward and valve 52 open.

, water under pressure enters chamber 59 from supply pipe 59 and the normal pressure of this water against the underside of piston 61 holds the same elevated against the resistance offered by spring 69, thereby holding valve 62 off the seat 63.

A small quantity of Water flows through the apertures and a corresponding amount 7 of water flows from the chamber above piston 61 out through opening 71, through pipe 56 to chamber 50 and thence through opening 51 to chamber 50 and from thence through pipe 55 to the ash-pit.

- When the temperature rises above minimum of the predetermined range, the increased pressure of the expansible vapor in container 36 acts upon diaphragm 39 to elevate that end of the lever 41 which carries plate 49. As a result, this plate is raised so that roller 48 rides against the low surface I) of said plate, thuspermitting bell crank 47 to change position and valve 52 to close under the influence of spring 54. This action shuts off the flow of water through housing 50 and consequently pressure is built up within chamber'59 equally above and below piston 61, and under the influence of spring 69, said piston is moved downward, thereby closing valve 62 upon seat 63.

Pressure from the lower portion of chamber 59 will build up in said chamberabove piston 61 by reason of vent opening 70 until diaphragm 66 is engaged with sufficient pressure to raise pin 68, thereby rocking arm and bearing upon pins 95 and 98 to disengage the points of pawls 94 and 97 from the teeth of ratchet wheel 87.

Sprin 91 will now act to rotate disk 87 100 anti-cl ock-wise until pin 89 is stopped by pin 89 I The instant the disk 87 is started in its partial rotary movement, roller 103 is raised out of notch 104 and travels on the periph 105 cry of said disk, thus moving rocker arm 102, thereb moving stem 82 downward and opening va ve 81, thereby permitting water above plate 73 to vent through opening 80.

The parts thus actuated maintain their posi-' 11 tions until the temperature of the furnace lowers sufliciently to permit diaphragm 39 to move downward, thereby actuating lever 41 and bringing the high surface a of plate 49 against roller 48. This movement ac- 5 tuates bell crank 47 and forces stem 53 downward, thereby unseating valve-52 and as soon as this takes place the pressure within chamber above piston 61 is relieved,

through opening 71, pipe 56, past open valve 52, and from thence through pipe 55'to the ash-pit. 1

As soon as the pressure above piston 61 is relieved, diaphragm 66 will move downward, thereby permitting the points of pawls 94 and 97 to reengage the ratchet teeth on disk 87 and the preponderance of pressure in the lower portion of chamber 59, will now raise piston 61, thereby elevating valve 62 from its seat.

The water from supply pipe 59 now passes from chamber 59 through passageway 64 and piston 72 is elevated by reason of pressure against the underside of plate 73, thereby unseating valve 74 and permitting the water to pass through passage-way 76 and pipe 78 to the hydraulic motor.

It will be understood that during these operations valve 81 is open and when piston 72 is raised as just stated, plate 73 will be moved against the underside of said valve and auxiliary valve 84 will close the vent opening 79, thereby cutting off the further flow of water through said vent opening and leaving upper surface of plate 7 3 subject to atmospheric pressure only.'

Water from main supply pipe 59 now has free passage to the hydraulic motor and the same will be operated to reciprocate plunger 24 in feed pipe 16 and fuel from hopper 15 will be fed forwardly through said feed pipe and will discharge from the upper inner end of said pipe onto the frusto-conical grate. Simultaneously, with this stoking operation arm 30 will be vibrated by reason of the engagement of roller 31 in the slot of arm 28, and by engagement with lever 32 shaft 29 will be rocked, thereby swinging arm 34 backward and forward and through the link connection 35 imparting movement to ring 21. This ring operates on rollers 22 and during operation, imparts rocking movement to all the grate sections 17 through the connections 20. As these grate sections are rocked, the ashes will be agitated in such manner as to cause same to drop through the openings in the a grate sections and pass into the ash-pit and simultaneously, the incandescent bed of fuel will be' elevated by the fresh fuel which discharges from the mouth of the feed pipe, which action tends to evenly distribute the entire mass of fuel over the grate surface.

As plunger 24 is thus actuated, arm 105 will be moved backward and forward, thereby rocking shaft 92 and spring-held pawl 94 carried thereby will successively engage the teeth of disk 87, thereby imparting intermittent rotary movement to said disk, the direction of said-movement being clockwise until the notch 104 has been brought in a position to receive roller 103. When this operation takes place arm 102 is actuated to permit stem 82 to raise, thereby closing valve 81 and as auxiliary valve 84 is removed from vent opening 79, water will pass through the last mentioned opening, thereby creating equal pressure above and below plate 73, whereupon spring 85 will act to move piston 72 downward, thereby closing valve 7 4 and cutting ofl the further supply of water to the hydraulic motor. This completes the cycle of operations necessary to bring about the automatic stoking of the furnace and the parts remain At the time lever 41 is actuated by the upward movement of diaphragm 39, that end of said lever to which the chains or cables 42 and 43 are connected will be moved downward, and as a result, draft damper 12 will be gradually moved to a closed position, thereby cutting off draft to the grate. Simultaneously, chain or cable 43 will be pulled downward, thereby opening check damper 14 which is located in smoke outlet pipe 13. Obviously, when the movement of lever 41 is reversed, draftdamper 12 will be opened and check damper closed.

At the completion of the cycle of stoking operations, the plunger 24 stops at its forward limit of movement, due to the fact that the step by step movement imparted to disk 87 is synchronous with the forward stroke of plunger and said disk arrives at the end of its driven movement at the termination of a forward stroke of said plunger. As plunger 24 is thus stopped at its forward limit of movement the opening from the hopper 15 into feed pipe 16 is closed, thus preventing draft of air from fuel hopper into said feed pipe, and when plunger is so positioned roller 31 occupies the lower end of the slot in arm 28 and all of the grate sections 17 occupy their normal positions so that they form a continuous inclined surface over which the fuel will readily distribute itself. (See Figs. 1 and 4.)

When the stoking of the furnace is effected electrically, the operations are as follows:

While the furnace is maintaining temperature below a predetermined range, the high edge of plate 49 bearing upon roller 48 of hell crank 47 holds contact pin 119 in engagement with pin 117, and thus establishing an electrical flow through circuit 120, pins 119 and 117, bracket 114, conductor 122, magnet coil 115, conductor 123, coil 124, and conductors 125 and 121. Both magnets 115 and 124 being energized, maintain their respective armatures 116 and 140 against their cores and thus the end of arm 139 provided with hook 142 is held in its elevated position and in engagement with book 146 on dog 145.

Whenso positioned, spring 129 is wound and hen released, rotates 'disk 127 anti clockwise.

When the temperature rises, lever 41 carrying plate 49 will be actuated to bring the spring 118, thereby breaking contact between pins 119 and 117. This opens the circuit in which magnets 124 and 115 are located, and as the same are deenergized, armature 140 carried by arm 139 will drop, which movement is brought about by spring 141, and thus the end of said arm carrying hook 142 will be moved downward, thereby disengaging hook 146 and pawls 134 and 136, and as soon as this release takes place, spring 129will act to move disk 127 anticlockwise, thereby engaging hook 148 behind hook 150 on arm 149, it being understood that said arm 149 and dog 145 on which hook 148 is formed form a part of the motor circuit as hereinafter more fully described. This action closes one of the openings in the circuit in which motor 109 is located, but said motor will not be operated, owing to the fact that the circuit is still open by reason of the break between pins 119 and 117.

When the free end of arm 139 moves downward as hereinbefore described, finger 143 engages pins 135 and 137, thereby disengaging the points of pawls 134 and 136 from the ratchet teeth on disk 127. The parts remain in the positions to which they have moved until the temperature drops below the predetermined range, whereupon lever 41 will be actuated to' move plate 49 so that the high edge thereof will engage roller 48 and actuate bell crank 47 to cause pin 119 to make contact with pin 117. This operation closes the circuits in which both magnets and the motor are located and as magnet 124 is energized, armature 140 and arm 139 will be pulled upward, thereby permitting pawls "134 and 136 to reengage the teeth of ratchet wheel 127.

Motor 109 will be operated to drive worm 110, worm wheel 111, and crank shaft 112,

- consequently imparting reciprocatory movementto plunger 24. As the plunger operates, arm 131 will be actuated, thereby rocking shaft 130 and causing point of pawl 134 to engage the teeth 128, thereby imparting intermittent rotary movement to disk 127.

The dog 145 is carried by ring 144 which is mounted on disk 127 and consequently arm 149 which is engaged by hook 148 on the rear end of said dog will be drawn upwardly until the hook 146 on the forward end of the dog engages and passes over the hook 142 on. arm 139, which movement releases hook 150 from hook 148, thereby permitting arm 149 to swing backward under the influence of sprin 151 and consequently breaking the circuit 1n which the motor is located.

it will be understood that the position of arm 149 is regulated by the position of pin 155 which can be located in any one of the apertures 154. This arrangement controls the length of time of operation of the motor and consequently controlling the number of strokes made by the plunger 24.

The motor circuit includes conductor 157 binding post 156, brush contact 157, ring 144, dog 145, arm 149, spring 151, binding post 152, conductor 153, and conductor 153":

The purpose of coil 115 and armature 116 is to insure perfect contact between pins 117 and 119 after the same have been first brought into contact with each other.

It will be readily understood that the hydraulic operating means and the electrically operated means can be readily interchanged, and in order to bring this about, it is only necessary to remove the pilot switch, control box, and motor of one mechanism and substitute therefor the pilot valve, control box, and motor of the other, or vice versa.

While I have shown and described a thermostat which is acted upon by fluid or vapor pressure, it will be understood that the same efiect can be brought about by thermostats of various forms, such as for instance, a thermostat wherein expansive movement is obtained by the action of heat upon certain metals.

A thermostat of this type is illustrated in Fig. 15, said thermostat including a number of rods or tubes of metal which have a high degree of expansibility when subjected to heat, the rod at one end of the series being connected to a fixed member and the rod at the opposite end of the series being connected to a bell crank which is adapted to operate the lever 41.

In some instances it may be found desirable to connect the rod at one end of the which latter is connected to an ordinary alarm clock 165.

To set this apparatus, spool 164 is rotated to wind a-portion of the chain or cable 162 thereupon, thus elevating weight 1.61. The alarm clock is set to release spool 164 at a predetermined hour, and when the clock marks the hour for which the release is set, spool 164 is released and will rotate to permit chain or cable 162 to unwind, thereby permitting weight 161 to move downward onto lever 41 and lowering same so that plate 49 actuates bell crank 47, which in turn, opens valve 52, which results in efi'ecting an operation of the stoking mechanism. Naturally, with the weight 161 added to lever 41, a comparatively higher degree of temperature will be required to affect the thermostat to again raise said lever for the movement through arm 34 and link 35 to ring 21, and consequently rocking all of the grate sections simultaneously.

Such manual operation of the grates provides for the dumping of foreign matter such as ashes, slate and other refuse, without disturbing the operation of the furnace and its stocking mechanism.

The operations of the stoking mechanisms are wholly automatic and their periods of operation are controlled by the rise and fall in temperature of the heat generated, and

the movement of plunger and consequent amount of fuel introduced during each cycle is determined by position of pin 89 when hydraulically operated and pin 155 when electricity is utilized.

By my improved method the stoking mechanism requires substantially no power during the periods of average temperature or during the time the temperature ranges from minimum to maximum, and said stoking mechanism depends only on the temperature and the changes thereof to efl'ect the stoking operation.

The controlling means associated with the stoking mechanism automatically terminates the activity or operation of said stoking mechanism, and such termination is entirely independent of the temperature and the changes thereof.

The stoking mechanism and grate of my improved construction are particularly adapted for using and burning comparatively fine waste coal or screenings as fuel, and in utilizing the underfeed principle with a grate of my improved construction, I am able to burn, and therefore eliminate, all smoke, and consequently obtaining practically perfect combustion.

It will be readily understood that minor changes in the size, form and construction of the various parts of the apparatus can be made and substituted for those herein shown and described, and further that other forms of apparatus can be designed for carrying out my improved method, which latter is set forth in the appended claims.

I claim:

1. The hereindescribed method of controlling the stoking of furnaces and the like, consisting in periodically introducing fuel into the furnace, each body of periodically introduced fuel being of predetermined volume and of an amount in excess of the immediate needs, utilizing the minimum and maximum degrees of heat from the furnace within a predetermined range of variation for effecting the succeeding fuel feeding operation, and simultaneously utilizing the temperature of the heat from the furnace for regulating and controlling the draft to and from the body of fuel within the furnace.

2. The hereindescribed method of controlling the stoking of furnaces and the like, consisting in periodically introducing fuel into the furnace, each body of periodically introduced fuel being of predetermined Volume and of an amount in excess of the immediate needs, utilizing the minimum and maximum degrees of heat from the furnace within a predetermined range of variation for effecting the succeeding fuel feeding operation, simultaneously utilizing the temperature of the heat from the furnace for regulating and controlling the draft to and from the body of fuel within the furnace, and agitating the body of fuel within the furnace simultaneously with the fuel feeding operation to effect the discharge of ashes therefrom.

3. The hereindescribed method of controlling the stoking of furnaces and the like, consisting in periodically introducing fuel onto the grate within the fire box of the furnace, each body of periodically introduced fuel being of predetermined volume and of an amount in excess of the immediate needs, utilizing the minimum and maximum degrees of temperature from the furnace within a predetermined range of variation for effecting the succeeding fuel feeding operation, and simultaneously utilizing the temperature of the heat from the furnace for controlling the draft to and from the body of burning fuel.

4. The hereindescribed method of controlling the stokingof furnaces and the like, consisting in periodically introducing fuel onto the grate within the fire box of the furnace, each body of periodically introduced fuel being of predetermined volume and of an amount in excess of the immediate needs, utilizing the minimum and maximum degrees of temperature from the furnacewithin a predetermined range of variation for effecting the succeeding fuel feeding operation, simultaneously utilizing the temperature of the heat from the furnace for controlling the draft to and from the body of burning fuel, and agitating the body of fuel on the grate simultaneously With the fuel feeding action to effect a discharge of ashes from said body of fuel.

5. The hereindescribed method of controlling the stoking of furnaces and the like, consisting in periodically introducing fuel into the furnace, each body of periodically introduced fuel being of predetermined volume and of an amount in excess of the immediate needs, utilizing the minimum and maximum degrees of heat from the furnace Within a predetermined range of variation for effecting the succeeding fuel feeding operation and utilizing the temperature of the heat from the furnace for controlling the combustion of the introduced fuel.

6. The hereindescribed method of controlling the stoking of furnaces and the like, consistmg in periodically introducing fuel into the furnace, each body of periodically introduced fuel being of predetermined yolume and of an amount in excess of the immediate needs, utilizing the minimum and maximum degrees of heat from the furnace Within a predetermined range of variation for eflecting the succeeding fuel feeding operation, and efiecting a control of the temperature resulting from the combustion of the introduced fuel to maintain comparatively high or low de rees of temperature but necessarily throug the predetermined range of variation which effects the periodic fuel feeding operation.

7. The hereindescribed method of controlling the stoking of furnaces and the like, consisting in periodically introducing fuel into the furnace, each body of periodically introduced fuel being of predetermined volume and of an amount in excess of the immediate needs, controlling and limiting the duration of each periodic fuel feeding action, utilizing the minimum and maximum degrees of heat from the furnace Within a predetermined range of variation for effecting the succeeding fuel feeding operation, and simultaneously utilizing the temperature of the heat from the furnace for regulating and controlling the draft to and from the body of fuel Within the furnace.

8. The hereindescribed method of controlling the stoking of furnaces and the like, consisting in periodically introducing fuel into the furnace, each body of periodically introduced fuel being of predetermined volume and of an amount in excess of the immediate needs, utilizing the minimum and maximum degrees of heat from the furnace within a predetermined range of variation for effecting the succeeding fuel feeding operation, simultaneously utilizing the temperature of the heat from the furnace for regulating and controlling the draft to and from the body of fuel Within the furnace, agitating the body of fuel Within the furnace simultaneously with the fuel feeding operation to effect the discharge of ashes therefrom, and regulating and controlling each ash discharge operation with relation to the volume of fuel introduced at the cor responding periodic fuel feeding action.

9. The hereindescribed method of con trolling the stoking of furnaces and the like consisting in periodically introducing fuel into the furnace, eachbody of introduced fuel being of predetermined volume and of an amount in excess of the immediate needs, utilizing the minimum and maximum degrees of heat from the furnace Within a predetermined range of Variation for effecting the succeeding fuel feeding operation, effect ing a termination of each periodic fuel feeding action Wholly independent of temperature changes, and utilizing the temperature of the heat from the furnace for controlling the combustion of the introduced fuel.

10. The hereindescribed method of controlling the stoking of furnaces and the like consisting in periodically introducing fuel into the furnace, each body of introduced fuel being of predetermined volume and of an amount in excess of the immediate needs, utilizin the minimum and maximum degrees 0' heat from the furnace Within a pre determined range of variation for effecting the succeeding fuel feeding operation, effecting a termination of each periodic fuel feeding action Wholly independent of temperature changes, utilizing the temperature of the heat from the furnace for controlling the combustion of the introduced fuel, and agitating the body of fuel ithin the furnace simultaneously With the fuel feeding action to effect the discharge .of ashes therefrom.

11. The hereindescribed method of controlling the stoking of furnaces and the like consisting in periodically introducing fuel onto the grate Within the fire box of'the furnace, each body of periodically introduced fuel being of predetermined volume and of an amount in excess of the immediate needs, eifecting a discharge of ashes from the'loWer portion of the bed of fuel on the grate simultaneously With each periodic fuel feeding action, and utilizing the minimum and maximum degrees of temperature through a predetermined range of variation for effecting the simultaneous periodic fuel feeding and ash discharge actions.

12. The hereindescribed method of controlling the stoking of furnaces and the like consisting in periodically introducing fuel onto the grate Within the fire box of the furnace, each body of perodically introduced fuel being of predetermined volume and of an amount in excess of the immediate needs, effecting a discharge of ashes from the lower portion of the bed of fuel on the grate simultaneously with each periodic fuel feeding action, utilizing the minimum and maximum degrees of temperature through a predetermined range of variation for effecting the simultaneous periodic fuel feeding and ash discharge actions, and utilizing the temperature of the heat from the furnace for controlling the draft to and from the body of fuel on the grate.

13. The hereindescribed method of controlling the stoking of furnaces and the like, which consists in intermittently feeding a predetermined amount of fuel onto the grate within the furnace, the volume of which fuel is in excess of the immediate requirements, utilizing the heat resulting from the combustion of said fuel for eflecting and controlling the fuel feeding operation, agitating the bed of fuel under combustion simultaneously with the feeding operation to effect a discharge of ashes from said bed of fuel and effecting the termination of the fuel feeding operation and the agitation of the fuel bed independently of the minimum and maximum degrees of temperature of the heat produced by the combustion of said fuel.

14:. The hereindescribed method of controlling the stoking of furnaces and the like which consists in intermittently feeding a predetermined amount of fuel onto the grate within the furnace, the volume of which fuel is in excess of the immediate requirements, utilizing the heat resulting from the combustion of said fuel for effecting and controlling the fuel feeding operation, agitating the bed of fuel under combustion simultaneously with the feeding operation to effect a discharge of ashes from said bed of fuel, efiecting the termination of the fuel feeding operation and the agitation of the fuel bed independently of the variation in temperature of the heat produced by the combustion of said fuel, converting the heat produced by the combustion of the fuel into motion, and utilizing the same to control the combustion of the introduced fuel.

15. The hereindescribed method of controlling the stoking of furnaces and the like consistlng in introducing into the furnace a volume of fuel which is in excess of the immediate requirements, converting the heat produced by the combustion of said fuel into motion and applying the same to control the combustion of the introduced fuel and utilizing the minimum and maximum temperatures within a limited and predetermined range for efi ecting periodic repetitions of the introduction of fuel.

17. The hereindescribed method of controlling .the stoking of furnaces and the like, consisting in periodically introducing a body of fuel into the furnace, the volume of which body of fuel is in excess of the immediate needs, utilizing the heat generated by the combustion of said fuel for controlling the temperature resulting from the combustion of the introduced fuel to maintain a comparatively high or low degree of temperature but necessarily through a limited and predetermined range of variation for effecting the periodical fuel feeding operations.

18. The hereindescribed method of controlling the stoking of furnaces and the like, consisting in effecting combustion of fuel within a furnace to produce heat and utilizing the temperature of said heat within a limited and predetermined range of variation for intermittently introducing into said furnace a body of fresh fuel, the volume of which is in excess of the immediate requirements.

19. The hereindescribed method of controlling the stoking of furnaces and the like consisting in introducing into the furnace a predetermined volume of fuel which is in excess of the immediate requirements, effecting the combustion of said fuel to produce heat and utilizing the minimum and maximum degrees of temperature of said heat within a limited and predetermined range of variation for intermittently introducing into the furnace predetermined volumes of fresh fuel, each volume of successively introduced fuel being in excess of theimmediate re quirements.

In testimony whereof I hereunto aflix my signature in the presence of two witnesses, this 17th day of February, 1915.

- EDWIN A. EMERY. Witnesses:

M. P. SMITH, M. A. HANDEL. 

